Gilead Sciences Inc today announced the initiation of ATHENA-1, a phase IV, randomised, double-blind, placebo-controlled study evaluating Letairis (ambrisentan 5 mg and 10 mg tablets) in patients with pulmonary arterial hypertension (PAH) demonstrating a sub-optimal response to sildenafil monotherapy.
ATHENA-1 is the first of several Phase IV Letairis studies Gilead plans to initiate in 2008 and 2009. Letairis is currently approved as a once-daily treatment for PAH (WHO Group 1) in patients with WHO functional class II or III symptoms to improve exercise capacity and delay clinical worsening.
“The PAH research community has made great progress over the last several decades in developing therapies for patients, including establishing an understanding of the role of therapies targeting different disease pathways,” said Norbert Bischofberger, Executive Vice President of Research and Development and Chief Scientific Officer at Gilead.
“With our Phase IV programme, we hope to contribute to the growing body of knowledge about this disease.”
ATHENA-1 will evaluate whether the addition of Letairis to sildenafil is safe and effective in PAH patients who have not demonstrated an optimal response on sildenafil therapy alone.
The primary objective of this study is to compare the change in pulmonary vascular resistance (PVR), or the resistance to blood flow caused by constricted lung blood vessels. A progressive increase in PVR is a measurable biological characteristic of PAH.